4AA to 4D Adapter Tube

thingiverse

I just purchased a new automatic trash can and it requires four D batteries connected in series to produce six volts. Unfortunately, I didn't have four D batteries or a six-volt adapter readily available. However, I do have plenty of AA batteries and a 3D printer on hand! I designed a custom tube to mimic the arrangement of four D batteries stacked end-to-end. Inside this tube, you'll need to insert four AA batteries. Since AA batteries are shorter than D batteries, you'll require a solid metal spacer about 1.5 inches long to fill the gap in the tube. I opted for a 1.5-inch #12 stainless steel pan head machine screw as my makeshift spacer. To assemble this setup, place your metal insert between two batteries in the center of the tube.